How the Napa Earthquake affected Bay Area sleepers

The South Napa Earthquake was the strongest to hit Northern California in 25 years. Our data science team wanted to quantify its effect on sleep by looking at the data recorded by Jawbone UP wearers in the Bay Area who track their sleep patterns.

Napa, Sonoma, Vallejo, and Fairfield were less than 15 miles from the epicenter. Almost all (93%) of the UP wearers in these cities suddenly woke up at 3:20AM when the quake struck. Farther from the epicenter, the impact was weaker and more people slept through the shaking. In San Francisco and Oakland, slightly more than half (55%) woke up. As we look even farther, the effect becomes progressively weaker — almost no UP wearers in Modesto and Santa Cruz (and others between 75 and 100 miles from the epicenter) were woken up by the earthquake, according to UP data.

Once awaken, it took the residents a long time to go back to sleep, especially in the areas that felt the shaking the strongest. In fact, 45% of UP wearers less than 15 miles from the epicenter stayed up the rest of the night.

Below is a visualization prepared by our Senior Data Scientist Brian Wilt that shows how the South Napa Earthquake’s effect on the UP wearers’ sleep changes with the distance from the epicenter.

We wish all the people in the Bay Area who were affected by the earthquake a speedy recovery and a good night’s sleep.

Technical Notes. This study was based on thousands of UP wearers in the Bay Area who track their sleep using UP by Jawbone. All results are statistically significant. All data is anonymized and presented in aggregate.